Add C-t transpose

Also in emacs, weechat.

catgirl.1

@@ -265,6 +265,8 @@ Move to end of line.
 Move right.
 .It Ic C-k
 Delete to end of line.
+.It Ic C-t
+Transpose characters.
 .It Ic C-u
 Delete to beginning of line.
 .It Ic C-w

chat.h

@@ -176,6 +176,7 @@ enum Edit {
 	EditDeletePrevWord,
 	EditDeleteNextWord,
 	EditPaste,
+	EditTranspose,
 	EditInsert,
 	EditComplete,
 	EditEnter,

edit.c

@@ -182,6 +182,15 @@ void edit(size_t id, enum Edit op, wchar_t ch) {
 			}
 		}
 
+		break; case EditTranspose: {
+			if (!pos || len < 2) break;
+			if (pos == len) pos--;
+			wchar_t t = buf[pos];
+			buf[pos] = buf[pos - 1];
+			buf[pos - 1] = t;
+			pos++;
+		}
+
 		break; case EditInsert: {
 			if (reserve(pos, 1)) {
 				buf[pos++] = ch;

ui.c

@@ -844,9 +844,10 @@ static void keyCtrl(wchar_t ch) {
 		break; case L'N': windowShow(windows.active->next);
 		break; case L'O': windowShow(windows.other);
 		break; case L'P': windowShow(windows.active->prev);
+		break; case L'T': edit(id, EditTranspose, 0);
 		break; case L'U': edit(id, EditDeleteHead, 0);
-		break; case L'W': edit(id, EditDeletePrevWord, 0);
 		break; case L'V': windowScroll(windows.active, -(PAGE_LINES - 2));
+		break; case L'W': edit(id, EditDeletePrevWord, 0);
 		break; case L'Y': edit(id, EditPaste, 0);
 	}
 }